Intellectual Disability Disorder

History

Plato wrote more than 2000 years ago in “The Republic” that no two persons are born exactly alike; but each differ from the

other by their intellectual abilities.

Alfred Binet (1857-1911)- Started measuring these intellectual abilities. He came with the idea about the mental

age and he understood the comparison of mental age and chronological age in assessing the intelligence.

Terman-Retain the Binet concept of mental age and adopted convenient index of intelligence suggested by the German psychologist William Stern. This index is the intelligence

quotient ,commonly know as the IQ. It expresses intelligence as a ratio of mental age to chronological age.

Intellectual Disability Disorder(Mental Retardation)

mental age chronological age

• If the MA is lower than the CA then IQ will be less than 100, If MA is Higher than CA then the IQ will be more than 100. It is considered IQ is below 70 as mentally retarded.

• In the 19th centaury the idiot was used for people with sever intellectual impairment, and imbecile for those with moderate impairment. When these words carries stigma, they were replaced by the term mental subnormality. Later it was replaced by the word mental retardation. Today it is called Intellectual Disability Disorder.

According to IQ mental retardation divide into-

• Mild- (IQ 70-50)• Moderate-(IQ 49-35)• Sever- (IQ 34-20)• Profound-(IQ below 20)

X 100IQ =

• Itard was a physician –in-chief at the Asylum for the Deaf and Dumb in Paris trained the “wild boy” found in Aveyron in 1801. This child was thought to have grown up in the wild, isolated from human beings. Itard made great efforts to train and educate the boy for 6 years but the training had been a failure.

• Seguin developed Itard methods to train and educate mentally retarded. He devised an educational program of physical exercises, moral instruction and graded tasks.

• 1913 Mental deficiency act of England and Wales

• 1960 Deinstitutionalization • Residential care in small homely units came up

Aetiology of mental retardation• Chromosomal abnormalities

• Down’s syndrome• Klinefelter’s syndrome• Turner’s syndrome• Fragile X syndrome

• Genetic abnormalities

• Phenylketonuria• Galactosaemia• Tay-sachs disease• Lesch-Nyhan syndrome• Neurofibromatosis (autosomal dominance

inheritance)• Tuberose sclerosis(Epiloia)-( autosomal dominant)

• Cranial malformations

• Hydrocephalus• Microcephalus

• Antenatal damage

• Infections (rubella,cytomegalo virus,syphilis,toxoplasmosis)

• Intoxications (alcohol, Lead, certain drugs)• Physical damage (birth injury,radiation,hypoxia)• Placental dysfunction• Endocrine disorders

(hypothyroidism,hypoparathyroidism)

• Perinatal Injury

• Birth asphyxia• Prematurity • Kernicterus

• Post-natal damage• Injury (accidental, child abuse)• Infections (encephalitis,meningitis)

• Malnutrition

• Subcultural mental retardation

Effects of mental retardation on the family

• When a new born child is found to be mentally retarded the parents are inevitably distressed. They often experience prolonged depression, guilt, shame, anger or anxiety. A few reject the child, while others become over involved in its care, sacrificing other important aspects of family life.

• Some parents get into arguments and end up in separation or divorce but most parents get adjusted to the situation take care of the child.

Definition of mental retardation

• It is unsatisfactory to define mental retardation in terms of intelligence quotient alone. Social criteria must be included, since a distinction must be made between people who can lead a normal or near normal life and those who cannot. In practice the most useful modern definition is probably the one used by American Association for Mental Deficiency, which define mental retardation as ‘sub-average general intellectual functioning which originated during the development period and is associated with impairment in adaptive behaviour’.

IQ

AB

70

• Assessment of mental retardation.– History taking and metal state examination– Physical examination– Developmental assessment(measuring

intelligence, language, motor performance and social skills)

– Behavioral assessment(ability to care himself, social abilities, sensory motor skills and any unusual behavior)

– Psychiatric assessment(psychiatric disorder, unrecognized epilepsy)

– Differential diagnosis(delayed maturation,

deafness, blindness, childhood autism, ADD )

Care of the mental retarded

• Among the new concepts of care the main principle is “normalization” an idea developed in Scandinavia in the 1960s. This term refers to the general approach of providing a pattern of life as near normal as possible. The least handicapped are brought up in their own homes and encouraged to lead a almost independent lives as adults. For the few who enter hospital the accommodation and activities are designed to be as close as possible to those of family life.

Mild mental retardation(IQ 50-70)

• People with mild retardation account for about 4/5 of the mentally retarded. They may have reasonable education though they need help with housing and employment or when under some stress.

Moderate mental retardation(IQ 35-49)

• People in this group account for about 12% of the mentally retarded. Most of them can talk or at least learn to communicate.

Severe mental retardation(IQ20-34)• In the pre-school years their development

is usually greatly slowed. Eventually many of them can be trained to look after them selves under close supervision and to communicate in a simple way.

Profound mental retardation(IQ below 20)

• People in this group account for less than 1% of mentally retarded. They may need care in a institution.

Treatments• It has been clearly shown that early start of training

programs are helpful. Therefore parents can start self care and living skill programs at home. Then send the child to pre- school early and continue educational programs.

• Later the child may enter school. Some need special class in normal school. Those who find difficult to follow may enter school for mentally retarded.

• Once they complete the education they may follow vocational training Centre.

• Types of behavior therapy( instructions, coaching, prompting, modeling, shaping, rewarding, role-play, seclusion)

Prevention of mental retardation(intellectual disability disorder)• Genetic counselling• Prenatal care Advice on diet alcohol and smoking Providing immunization against rubella Amniocentesis, fetoscopy and ultra sound

scanning Detection and treatment of rhesus incompatibility Special care for mothers with diabetes mellitus

• Good obstetric care for mother• Post natal care

All infants should be tested for phenylketonuria, hypothyroidism and galactosaemia

Special care for pre-mature and low birth weight infants can prevent mental retardation

Education and supporting the mothers could prevent sub-cultural mental retardation

Question

Why Psychiatric disorders are common in intellectual disability disordered people(mental retardation)?